Make arm64 compatible

linux/ubuntu/scripts/pwsh.sh

@@ -3,8 +3,26 @@
 set -Eeuxo pipefail
 
 printf "\n\t🐋 Installing PowerShell 🐋\t\n"
-sudo apt-get -yq update
-sudo apt-get -yq install powershell
+
+# While an linux/amd64 platform installation can use apt-get, the linux/arm64
+# platform installation can't as described here:
+# https://docs.microsoft.com/en-us/powershell/scripting/install/installing-powershell-core-on-linux?view=powershell-7.1#support-for-arm-processors
+#
+# Due to that, we rely on the binary installation method for both platforms, as
+# described here:
+# https://docs.microsoft.com/en-us/powershell/scripting/install/installing-powershell-core-on-linux?view=powershell-7.1#linux
+#
+
+ARCH=$(uname -m)
+if [ "$ARCH" = x86_64 ]; then ARCH=x64; fi
+if [ "$ARCH" = aarch64 ]; then ARCH=arm64; fi
+VER=$(curl --silent "https://api.github.com/repos/PowerShell/PowerShell/releases/latest" | jq -r .tag_name)
+curl -L -o /tmp/powershell.tar.gz "https://github.com/PowerShell/PowerShell/releases/download/$VER/powershell-${VER:1}-linux-$ARCH.tar.gz"
+sudo mkdir -p "/opt/microsoft/powershell/${VER:1:1}"
+sudo tar zxf /tmp/powershell.tar.gz -C "/opt/microsoft/powershell/${VER:1:1}"
+sudo chmod +x "/opt/microsoft/powershell/${VER:1:1}/pwsh"
+sudo ln -s "/opt/microsoft/powershell/${VER:1:1}/pwsh" /usr/bin/pwsh
+rm /tmp/powershell.tar.gz
 
 printf "\n\t🐋 Installed PWSH 🐋\t\n"
 pwsh -v
@@ -13,12 +31,6 @@ printf "\n\t🐋 Installing PowerShell modules 🐋\t\n"
 modules=("MarkdownPS" "Pester" "PSScriptAnalyzer")
 
 for mod in "${modules[@]}"; do
-    printf "\n\t🐋 Installing %s 🐋\t\n" "${mod}"
-    pwsh -nol -nop -c "Install-Module -Name ${mod} -Scope AllUsers -SkipPublisherCheck -Force"
+  printf "\n\t🐋 Installing %s 🐋\t\n" "${mod}"
+  pwsh -nol -nop -c "Install-Module -Name ${mod} -Scope AllUsers -SkipPublisherCheck -Force"
 done
-
-printf "\n\t🐋 Cleaning image 🐋\t\n"
-apt-get clean
-rm -rf /var/cache/* /var/log/* /var/lib/apt/lists/* /tmp/* || echo 'Failed to delete directories'
-
-printf "\n\t🐋 Cleaned up image 🐋\t\n"